Protective helmet comprising a mechanical sizer-adjusting system

ABSTRACT

The present invention relates to a protective helmet (1) comprising shock-absorbing means in the form of movement discs (6) each comprising an outer ring (7); a central “bead” or tenon (9); a plurality of deformable arms (8), both ends of which substantially tangentially connect the outer ring (7) and radially connect the central bead (9). The deformable arms (8) have a length of at least 1.5 times the radius of the outer ring (7) so as to be able to form, by deformation, a conical and elastic structure whereof the central bead (9) is located at the apex and is in contact with the rigid outer shell (2). The movement discs (6) are further secured to the inner face of the rigid outer shell (2), such that in the static position, the inner structure (3) is separated from the rigid outer shell (2) by an interval (14).

SUBJECT MATTER OF THE INVENTION

The present, invention relates to a protective helmet, for use forexample in the field of sports, road or military safety, having animproved shock absorption capability owing to an optimizedshock-absorption device. The protective helmet also comprises animprovement to the system for adjusting the helmet to the size of thehead of the user.

BACKGROUND OF THE INVENTION

Protective helmets generally comprise a rigid outer structuresurrounding an inner shock-absorbing structure, the two structures beingconnected by connecting elements. In order to absorb the force ofimpacts and dampen shocks so as to limit their transmissions to the headof the user, the two structures can often slide relative to one another.

The inner shock-absorbing layer may be made from a material generallyabsorbing energy and/or also may comprise occasional or localshock-absorbing elements deforming under the effect of a force, forexample springs. In some helmets, this inner layer also comprises meansfor adjusting the helmet to the size of the head of the user.

The difficulty lies in providing a shock-absorbing structure absorbingboth the energy of a radial impact and that of a tangential impact.

Document US 2016/073723 A1 discloses a helmet comprising two partssliding relative to one another as well as a connection means betweenthe two parts, associated with an element able to absorb the energyowing to its elasticity, for example by procuring a spring- orshock-absorbing force. These connection means are devices able to absorbenergy owing to their elasticity. When a tangential or oblique force isapplied on the helmet, a relative movement between the two parts of thehelmet occurs. The energy is absorbed by the connection means, whichdeforms under the action of the force applied on the helmet. In thisdocument, the shock-absorbing device is fastened, glued, or molded inone of the two radial parts of the helmet, and may, as an example, havethe form of a spring with flat spirals.

Document US 2017/172242 A1 describes a helmet comprising an outer shell,a shock-absorbing layer inside the outer shell and again an inner shellthat is arranged inside the shock-absorbing layer. The inner layer isconfigured to slide relative to the shock-absorbing layer and comprisesa certain number of openings with a deflector inside each opening. Eachdeflector comprises a body connected to the shock-absorbing layer, aperipheral border connected to the opening in which it is received, aswell as a certain number of deformable spokes extending between the bodyand the border. The deflector makes it possible to absorb the energyfrom the shock received on the outer shell owing to its deformation.

Document GB 2,541,760 A relates to energy-absorbing systems. A flexibleand deformable energy-absorbing system comprises a body with an innercell and an outer cell (for example, rings), the inner cell being heldin position in the outer cell by lateral straps. The inner cellcomprises an element in relief (“overhang”) relative to the outer cell,able to be inserted into another cell having a recessed geometry, inorder to make it possible to absorb the energy of a shock. During theimpact, the overhang will be pushed into the inner cell of anotherelement to react the forces, in this way dissipating part of the energyof the impact.

Furthermore, regarding systems for adjusting the size of the helmet onthe head of the user, different tightening means exist.

Document US 2013/283507 A1 discloses a helmet comprising a rigid outershell and an inner adjusting structure in which the head of the userengages. The outer shell and the inner structure are coupled using asystem of tightening cables or straps. The user can adjust the size ofthe inner structure by modifying the tension of the tightening cablesthat are available in the helmet, using a toothed wheel cooperating withtwo parallel toothed tabs situated at, the rear of the helmet, i.e., apinion-rack system.

Document US 2013/312163 A1 describes a helmet with an inner structurewith automatic adjustment. The inner structure comprises a rear basketand a front headband, as well as a means for tensioning the basket andthe band around the head of a user. The tensioning means comprises aspring and a cable passing along the basket and attached to the band,the spring making it possible to stretch the front headband via thecable.

AIMS OF THE INVENTION

The present invention aims to provide a solution making it possible toimprove the dampening of small shocks received by a protective helmet,leading to continuously repositioning the helmet in its initial balancedposition on the head.

Another aim sought by the invention is to provide a solution allowing awide adjustment range of the helmet and adaptation to all types of heador morphology, thus offering maximum comfort.

In particular, the invention aims to allow an easy adjustment when thehelmet is already positioned on the head of the user.

The invention also seeks to improve the ventilation of the helmet by thefact that the adjustment system is “floating”, i.e., attached only atcertain points.

MAIN FEATURES OF THE INVENTION

The present invention relates to a protective helmet comprising:

-   -   a rigid outer shell;    -   an inner structure located inside the rigid outer shell and        adjustable to the head of a user, said inner structure        comprising a basket and a band, the basket and the band being        intended to be positioned respectively at the back and at the        front of the head, and at least two separate shock-absorbing        means secured to the band;    -   adjusting means of the inner structure;        characterized in that the shock-absorbing means are movement        discs each comprising:    -   an outer ring;    -   a central “bead” or tenon;    -   a plurality of deformable arms, both ends of which substantially    -   tangentially connect the outer ring and radially connect the        central bead; the deformable arms having a length of at least        1.5 times the radius of the outer ring so as to be able to form,        by deformation, a conical and elastic structure whereof the        central bead is located at the top and is in contact with the        rigid outer shell, and in that the movement discs are further        secured to the inner face of the rigid outer shell, such that in        the static position, the inner structure is separated from the        rigid outer shell by an interval.

According to preferred embodiments of the invention, the protectivehelmet further comprises one of the following features, or a suitablecombination of several of these features:

-   -   the adjusting means of the inner structure comprise:        -   a pinion-rack system secured to the basket and comprising a            tightening wheel and a toothed sliding tab;        -   a tightening cable extending said band of the inner            structure at a first end and ending at a second end with the            toothed sliding tab;        -   the tightening wheel being able to cooperate with the,            toothed sliding tab so as to shorten/stretch or to            extend/relax the tightening cable to increase the available            space between the band and the basket of the inner            structure;    -   the band comprises at least one azimuthal part relative to the        helmet laterally provided on each side of the frontal part of        the helmet with at least one movement disc;    -   the band further comprises a meridian part relative to the        helmet provided with at least one movement disc;    -   the rigid outer shell is made in the form of an outer layer made        from a rigid material, such as acrylonitrile butadiene styrene        (ABS) or polycarbonate (PC), topping an absorbent layer, made        for example from expanded polystyrene (EPS) or expanded        polypropylene (EPP);    -   the inner structure is made from polyamide (PA);    -   the movement discs are made from a rigid plastic material and        are molded by injection or by 3D printing in a single piece;    -   the movement discs are made from the same material as the band,        their shape giving them their elasticity;

the adjusting means of the inner structure comprise two tighteningcables, each respectively connected to one end of the band and togetherto the toothed sliding tab, the two tightening cables being arrangedsymmetrically on each side of the basket, owing to cable passagebridges.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 schematically shows a first view of an example protective helmetaccording to the present invention.

FIG. 2 schematically shows another view of an example protective helmetaccording to the present invention.

FIG. 3 schematically shows a sectional view of the protective helmetaccording to FIG. 1.

FIG. 4 schematically shows a sectional view of the protective helmet,done along a plane perpendicular to the section plane of FIG. 3.

FIG. 5 schematically shows a view of the inner structure of theprotective helmet according to the invention.

FIG. 6 shows an example shock-absorbing means of the protective helmetaccording to the present invention.

FIG. 7 shows an example for the tightening wheel and for the toothedsliding tab of the inner structure of the protective helmet according tothe present invention.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the protective helmet 1 recommended by the presentinvention is shown in FIGS. 1 to 5. The helmet 1 comprises a rigid outershell 2, either solid, or having ventilation apertures, made for examplein the form of an outer layer made from a rigid material, such asacrylonitrile butadiene styrene (ABS), polycarbonate (PC), etc. and anabsorbent layer made from expanded polystyrene (EPS), expandedpolypropylene (EPP), etc. An inner structure 3 coming directly intocontact with the user's head is positioned radially inside the outershell 2. This inner structure 3, for example made from polyamide (PA),is adjustable to the size of the user's head, owing to adjusting meanslocated partially outside the outer shell 2, at the top of theprotective helmet 1 (see hereinafter). The outer shell 2 and the innerstructure 3 can move relative to one another, such that an impact on theouter shell is only transmitted to the user's head in a limited manner.Indeed, if a shock is applied to the protective helmet, the force ofthis shock will be partially absorbed by the relative movement of theouter shell 2 with respect to the inner structure 3.

As shown in FIGS. 4 and 5, the inner structure 3 comprises a basket 4, aband 5 and a plurality (at least three) of separate shock-absorbingmeans 6. The band 5 and the basket 4 surround the user's head when thelatter is wearing the helmet 1, respectively at the back and at thefront of the head. Thus, the space left available for the head is madevariable owing to the adjusting means of the inner structure. Theseadjusting means comprise one or several tightening cables 12, a toothedwheel 10 and a toothed sliding tab 11 cooperating with the toothed wheel10, making up a pinion-rack system (the sliding tab slides in astructure secured to the basket). The tightening cable 12 is connected,at one of its ends, to the band 5 and at the other of its ends, to thetoothed sliding tab 11. The toothed tab 11 cooperates with the toothedwheel 10 such that the user can stretch or relax the cable 12 by turningthe toothed wheel 10 to the right or to the left, which will, in thisway, move the toothed sliding tab 11. In this way, it is possible toincrease or decrease the perimeter of the band 5. Furthermore, thetightening cables 12, of which there are two in the example, movesymmetrically and in the same direction.

Moreover, the tightening cables 12 are slidingly connected to the basket4 by passage bridges 13, which are open or closed. The basket 4therefore allows the passage of the tightening cables 12 and groupstogether the mechanical components (pinion-rack system 10, 11).

Advantageously, the toothed wheel 10 and the associated tab 11 arelocated on the outer shell 2, at the top of the protective helmet 1. Thepositioning or the passage of these elements on the outer face of thehelmet are possible owing to openings in the outer shell 2. In this way,the user can easily modify the size of the protective helmet when thelatter is already on his head, which greatly facilitates the adjustmentof the inner structure to the size of the head of the user.

The adjusting system can be moved, in its entirety, from front to backby an outside manipulation of the helmet. The movement of the adjustingsystem positioned externally allows a manipulation thereof, when thehelmet is worn on the head, in order to position the basket in its mostcomfortable position.

Furthermore, the band 5 of the inner structure comprises, aside from thetightening cable 12, shock-absorbing means 6. As shown in FIG. 6, thelatter are preferably made up of a disc comprising an outer ring 7connecting a central bead or tenon or rod 9, providing a certain reliefto the central part of the disc, using a plurality of connecting arms 8.More specifically, the connecting arms 8 have their first end connectingthe outer ring 7 substantially tangentially, and their second endconnecting the central bead 9 radially. In this way, the deformable arms8 have a length greater than the length of the radius of the ring 7, andpreferably have a length of at least 1.5 times, and preferably at least2 times, that of the radius of the ring 7. Alternatively, there may onlybe one connecting arm 8 in the form of an Archimedes spiral. In thisway, and owing to the shape of the connecting arm(s) 8, theshock-absorbing means 6 can deform orthogonally relative to the ring 7in order to form a three-dimensional structure resembling a cone, withthe central bead 9 being located at the top thereof.

As shown in FIG. 6, this structure allows, once the central ball 9 ismoved away from the plane of the ring 7, an elastic return thereof intosaid plane. Thus, as shown in FIG. 3, the sizer 3 according to thepresent invention is provided to be at a distance of several millimetersfrom the inner face of the rigid outer shell 2. Since the central bead 9is secured to this inner face, in the helmet in the static position, theshock-absorbing or movement disc 6 is in the more or less “conical”position, the return force of the element 6 offsetting the traction ofthe rigid outer shell 2 on the bead 6.

In the inner structure of the helmet, the shock-absorbing means 6 aresituated such that each bead 9 can be connected to the inner face of therigid outer shell 2. When an impact radially occurs on the helmet, theshock-absorbing means 6 will tend to be flattened by compression, thecentral bead 9 then being in the same plane as the outer ring 7,absorbing part of the energy of the applied force. The absorption oftangential shocks is of course also done by the shock-absorbing discs 6.Thus, during an impact, the shock-absorbing discs 6, and therefore theinner adjusting structure 3, can move in all directions (i.e., radialand tangential), by following the movement of the head, independently ofthe rigid outer part of the helmet 2.

When the helmet is adjusted on the user's head:

-   -   in the static position, the movement discs 6 fastened at some        points on the helmet make it possible to keep a space between        the helmet and the band in order to allow a passage of air and        to improve the ventilation of the helmet. Due to its geometry,        each movement disc 6 can stretch greatly (during the movement        normal to the inner surface of the helmet) in order to best        adapt to the different head sizes and morphologies (European,        Asian, etc. head type);    -   during dynamic use, the movement discs 6 allow a slight        multidirectional movement of the helmet independently of the        movement of the head in order to allow the helmet to return        automatically to its initial equilibrium position during small        impacts (for example, forest branches during “mountain bike”        use)

LIST OF REFERENCE SYMBOLS

1. Protective helmet

2. Rigid outer shell

3. Inner structure (sizer)

4. Basket

5. Band

6. Shock-absorbing element (movement disc)

7. Outer ring of the shock-absorbing element

8. Deformable arm of the shock-absorbing element

9. Central “bead” of the shock-absorbing element

10. Toothed tightening wheel

11. Toothed sliding tab

12. Tightening cable

13. Cable passage bridge

14. Interval between sizer and rigid outer shell

1. A protective helmet (1) comprising: a rigid outer shell (2); an innerstructure (3) located inside the rigid outer shell (2) and adjustable tothe head of a user, said inner structure (3) comprising a basket (4) anda band (5), the basket (4) and the band (5) being intended to bepositioned respectively at the back and at the front of the head, and atleast two separate shock-absorbing means (6) secured to the band (5);adjusting means of the inner structure (3); characterized in that theshock-absorbing means are movement discs (6) each comprising: an outerring (7); a central “bead” or tenon (9); a plurality of deformable arms(8), both ends of which substantially tangentially connect the outerring (7) and radially connect the central bead (9); the deformable arms(8) having a length of at least 1.5 times the radius of the outer ring(7) so as to be able to form, by deformation, a conical and elasticstructure whereof the central bead (9) is located at the top and is incontact with the rigid outer shell (2), and in that the movement discs(6) are further secured to the inner face of the rigid outer shell (2),such that in the static position, the inner structure (3) is separatedfrom the rigid outer shell (2) by an interval (14).
 2. The protectivehelmet (1) according to claim 1, characterized in that the means foradjusting the inner structure (3) comprise: a pinion-rack system (10,11) secured to the basket (4) and comprising a tightening wheel (10) anda toothed sliding tab (11); a tightening cable (12) extending said band(5) of the inner structure (3) at a first end and ending at a second endwith the toothed sliding tab (11); the tightening wheel (10) being ableto cooperate with the toothed sliding tab (11) so as to shorten/stretchor to extend/relax the tightening cable (12) to increase the availablespace between the band (5) and the basket (4) of the inner structure(3).
 3. The protective helmet (1) according to claim 1, characterized inthat the band (5) comprises at least one azimuthal part relative to thehelmet laterally provided on each side of the frontal part of the helmetwith at least one movement disc (6).
 4. The protective helmet (1)according to claim 3, characterized in that the band (5) furthercomprises a meridian part relative to the helmet provided with at leastone movement disc (6).
 5. The protective helmet according to claim 1,characterized in that the rigid outer shell (2) is made in the form ofan outer layer made from a rigid material, such as acrylonitrilebutadiene styrene (ABS) or polycarbonate (PC), topping an absorbentlayer, made for example from expanded polystyrene (EPS) or expandedpolypropylene (EPP).
 6. The protective helmet according to claim 1,characterized in that the inner structure (3) is made from polyamide(PA).
 7. The protective helmet (1) according to claim 1, characterizedin that the movement discs (6) are made from a rigid plastic materialand are molded by injection or by 3D printing in a single piece.
 8. Theprotective helmet (1) according to claim 7, characterized in that themovement discs (6) are made from the same material as the band (5),their shape giving them their elasticity.
 9. The protective helmet (1)according to claim 2, characterized in that the adjusting means of theinner structure (3) comprise two tightening cables (12), eachrespectively connected to one end of the band (5) and together to thetoothed sliding tab (11), the two tightening cables (12) being arrangedsymmetrically on each side of the basket (4), owing to cable passagebridges (13).
 10. The protective helmet (1) according to claim 2,characterized in that the pinion-rack system (10, 11) for the adjustmentof the inner structure by the user is situated on the outer face of therigid shell (2) of the helmet (1) and therefore accessible to the useronce the helmet (1) is placed on his head, owing to apertures providedin the rigid outer shell (2) for the passage of the basket (4) andtightening cables (12) from the inside to the outside of the helmet (1)and owing to a sigmoid shape of the basket (4).